This project involves a multifaceted, interdisciplinary program of research projects focusing on the field of reproductive endocrinology. This program involves the coordinated efforts of 8 senior investigators in 4 University departments: Anatomy, Pathology, Pediatrics, and Biol. Sciences. The approaches involved range from the cellular and molecular to the morphological and physiological, with extensive integration of the various levels. Major research emphasis is placed on the following problem areas: regulation of gonadotropin secretion, localization of GnRH in hypothalamus, estradiol action in corpus luteum, LH-receptor and ovarian function, and non-histone chromatin proteins and reproductive hormone action. Using our various types of expertise in exploring these problems, it is hoped to obtain a better understanding of reproductive endocrinology and physiology which can then form the basis for new approaches to contraception and population problems. BIBLIOGRAPHIC REFERENCES: Baker, B.L,, and Yu, Y.Y., Immunocytochemical analysis of cells in the pars tuberalis of the rat hypophysis with antisera to hormones of the pars distalis, Cell. Tiss. Res. 156: 443, 1975. Baker, B.L., Dermody, W.C., and Reel, J.R., Distribution of gonadotropin-releasing hormone in the rat brain as observed with immunocytochemistry, Endocrinology, 97: 125, 1975.